The invention relates to a construction for a reed on a textile loom which spaces the individual warp ends on the loom and holds them parallel as the reed pushes the filling yarn into place at the fell of the fabric. As each pick of the filling yarn is inserted through the shed of the warp yarns, the reed beats up the filling yarn against the already woven part of the fabric in an action commonly referred to as beat-up. The reed typically includes a frame in which a plurality of wire dents are carried to provide spaces therebetween in which the warp yarn ends are guided. One side of the frame is clamped to a moving beam on the loom which moves the reed back and forth to produce the beat-up action. One side of the reed is commonly referred to as the beat-up side as it faces the fell of the cloth being woven. The wire dents are normally fairly rigid so that they may beat up the filling yarn against the fabric already woven.
The problem occurs that the warp yarns forming a shed for insertion of the filling yarn to pass often stick or cling together due to their close proximity to one another. This often results in breakages when the reed moves forward over the warp yarn ends during beat-up. Slubs, knots, and other imperfections in the individual warp yarn ends also tend to catch on the dents due to the narrow spacing therebetween which causes breakage of the warp yarn ends. Warp breaks result in time consuming loom stops or fabric imperfections, both of which are costly in terms of time and production.
Many types of cloth such as very fine fabrics, require a large number of warp yarn ends per inch of reed and it is difficult, if not impossible, to arrange the dents to provide a passage space for each warp end rendering paralleling of the warp ends difficult during shedding and beating-up.
In an attempt to more evenly space the warp yarn ends and hold them parallel as the reed beats up each pick of the filling yarn, the use of two rows of dents has been proposed whereby the front row beats the filling yarn against the woven fabric and the back row of dents are arranged to more evenly space the warp ends. Since there are more dents to hold the yarns parallel without a corresponding decrease in spacing distance the warp ends pass freely through the reed. In this manner, ends are spaced more evenly without construction of the passage spaces. Typical of the prior double dent reed constructions are those shown in U.S. Pat. No. 1,146,478, Dutch Pat. No. 2,823,222, and British Pat. No. 8,525.
However, it has been found that considerable resistance to the passing of the warp ends may still be had in the back row of dents due in part to their rigidity and their staggered path which requires the warp yarns to assume a somewhat tortuous path through the reed.
The prior constructions also tend to be heavier than single dent reeds which makes them less desirable for use on modern high speed looms. The inertial forces on the upper free side of the reed frame are considerable when utilized on high speed loom operations.
Accordingly, an important object of the present invention is to provide a double dent reed construction for a loom which permits the warp yarn ends to pass more freely through the dent spaces and reduces accumulation of lint and warp breakages.
Still another important object of the present invention is to provide a double dent reed construction for a loom which includes a first row of dents on the beat-up side of the reed which are rigid for beating-up the filling yarns and a second row of dents which are more flexible than the first row of dents which assist in holding the warp ends parallel yet facilitate free passage of the warp yarn ends through the dent spaces.
Still another important object of the present invention is to provide a double dent reed construction for a high speed loom in which the free side of the reed frame is lighter than the clamping side of the frame to reduce the inertial forces on the frame and loom during beat-up.
Yet another important object of the present invention is to provide a double dent reed construction for a loom which has a first and second row of staggered dents carried in the frame by means of upper and lower support bars wherein the upper support bar on the free side of the frame is lighter in weight than the lower support bar and by means of which the first row of dents are supported more rigidly in the frame for beating-up the filling yarns.